Circuit breaker



L. C. REED CIRCUIT BREAKER Oct. 24, 1933.

Filed April 22, 1929 4 Sheets-Sheet l JNVENTOE QTTOENEY L. C. REED CIRCUIT BREAKER Oct. 24, 1933.

Filed April 22. 1929 4 Sheets-Sheet 2 Oct. 24, 1933. L, c. REED 1,931,507

CIRCUIT BREAKER Filed April 22, 1929 4 Sheets-Sheet 3' ii z 1 6g w L. C. REED Oct. 24, 1933.

CIRCUIT BREAKER Filed April 22, 1929 4 Sheets-Sheet 4 J 5 .JNVENTOR.

TTORNEY Patented ca. 24, 1933 'UITED srArEs PATENT OFFICE This invention relates generally to apparatus for interrupting and protecting electric circuits and, more particularly, to certain new and useful improvements in such apparatus of the type commonly known as circuit-breakers.

To obtain an interruption of an A. C. or D. C. circuit in the shortest possible time after a short circuit occurs involves many factors. Conventional methods heretofore employed will not, so far as I am advised, obtain the results required, more particularly in respect to A. C. breakers. D. C. high speed breakers for single pole service have been designed and placed in operation, that have shown as low as .003 seconds for the break period. Nothing, so far as I am aware, anywhere near this time has been obtained. with A. C. breakers, and about the best performance that is recorded is .016 seconds for the rupturing time or the circuit. To obtain a rupturing time on A. C. shorts of .003 seconds and under means that the time elements of each link in the rupturing mechanism must be reduced to its lowest time factor. Furthermore, the speed of the moving contacts must be such that no opportunity to volatilize the contact points is given, and what current, if any, is carried across the arc must be through the medium of ionized air and not metallic or carbon vapor. The contacts must be separated at a high speed at the instant of break and reach a distance apart greater than the jump gap constant of the circuit voltage interrupted before the expiration of any remaining half cycle period in which the short occurs.

The most desi able solution would be to interrupt the current in a short circuit at as close a value as possible to the overload setting point of the breaker. In other words, at some value under 1065 per cent overload instead of at some value representing the capacity of the system in which the short occurs. A system protected by circuit breakers in which the short is limited to the above values would be free from disastrous interruptions and much property loss.

In order to accomplish this result, certain fundamentals must be laid down and adhered to. If the toggle release type of circuitclosing mechanism is sed, the time element'to point of circuit rupture allotted to this portion of the mechanism must be determined, and the release so designed as to come within the time allotted. l he means set in motion by the short for releasing the toggle must have a definite allotted operating time. The contact arms and linkage have a definite time element of operation, which is wholly mechanical and dependent upon the actuatingforce, the speed of the moving parts, and the. weights. There is still another time element involved which is wholly electrical-and on A. C. systems is a variable dependent upon the point on the voltage wave at which the short occurs. The current grows at rates dependent on this'point and reaches values at which the mechanism trips, which may vary between 50 to 100% of the time allotted for this portion of the total time cycle.

My, present invention has hence for its objects the provision of an efficient circuit breaking or interrupting apparatus 'for both A. C. and D. 0.

systems adapted for the solution of the various problems stated and the accomplishment in ape proximately the lowest possible time of the results sought.

Andwith the above and other objects in view, my invention resides in the-novel features of form, construction,- arrangement, i and combination of parts hereinafter described and pointed out in the claims v Figure 2 is a plan view of-the same; 85

FigureS is a view similar to Figure '1, the several parts, however, being. shown in. a momentary portion of thekmovement thereof to circuit-opening position;

Figure 4 is a sectional view similar to Figure 5, the engageable-ends of the contact-members of the breaker proper being in widely spaced circuit-opening position as when the circuitbreaker is automatically actuated or tripped as 9 on an overload in'the circuit;

Figure 5 is a sectional view approximately along the line 55, Figure 2, the engageableends or" the contact-members being in circuitclosing engagement; v

Figure 6 is an enlarged detail view of the engageable-ends of a co-operating pair of the contact-members;

Figure 7 is a sectional view through the apparatus approximately along the line 77, Figure 5; v

Figure 8 is an enlarged sectional view along the line 8S, Figure 2;

Figure 9 is a diagrammatic view of the electric circuit associated with the circuit-breaker,

For the present, it may be stated that the breaker line 2 in Figure 10.

a modified form of the time delay device being shown in connection therewith;

Figure 10 is an electro-mechanical diagram illustrating the relationship between the circuitbreaker and its associated circuit; and

Figure 11 is a fragmentary portion of Figure 4, showing a detail of the modified form of time delay device as employed in connection therewlth, other portions being omitted.

Referring now more in detail and by reference characters to the present drawings, which illustrate a preferred embodiment of my invention, a general outline of the apparatus will first be given. For such purpose, reference is particularly made to Figure 10, which diagrammatically illustrates according to my invention an arrangement or hook-up" for the protection of a threephase alternating current transmission line, of which A designates the protecting or associated breaker actuating circuit, and B, B designate the transmission or current supplying circuit, or, in other words, the circuit to be protected, B being the line side and B being the other or "load" side of the circuit, the latter being connected or disconnected from the former by a switching device or breaker proper C of suitable characteristics. Such breaker is preferably of the type shown and fully described in my copendlng application, Serial No. 319480. I shall later more fully describe the present breaker C.

0 comprises opposed swingable contact-members 1 adapted for actuation, through instrumentalities later mentioned, by a rotatably movable or rockable main shaft, indicated by the dot-dash Normally the shaft 2 is yieldingly urged in circuit-opening position by means comprising another shaft, indicated by the dot-dash line 3 in Figure 10, fixed upon which is one or more spring-set or pressed arms '4, 4', co-operating with a cam-lever 5 fixed, in

turn, on the shaft 2. Other or so-called armature arms 6 also fixed on the shaft 3 are electromagnetically associated with respective series coils 7, 7, in two of the leads 8, 3, on the load side B of the protected circuit B, B, there being two such coils 7, '7, shown in the present instance, although, of course, there may be more or less than two, at the option of the person constructing the apparatus or according to the requirements of the circuit to be protected.

The series coils 7, 7, are adapted, as will presently appear, to utilize the surge of current occurring on occasion of an overload condition in the protected circuit for circuit opening actuation 01' the circuit-breaker C, which is also directly actuated to circuit-opening position through rocking of the main shaft 2 by the spring-pressed arms 4, 4', the associated circult A being designed to afford protection against any abnormal condition, such as either overload, under-voltage, or no voltage conditions.

Operatively associated with the main shaft 2, is a toggle mechanism D comprising arms 9 and 10, normally partially upset or unbalanced, that is to say, the toggle mechanism is, so to speak, cracked or bent from linear alignment of its toggle arms 9, 10, the knee of the toggle being pivotally connected by a link 11 with a swingable armature .12 electro-magnetically associated with a holding coil or magnet 13 connected by a circuit 13 across two of the phases of the line side B of the breaker circuit, that is to say, across any two of the line leads 1'7, 17. More particularly, the arrangement of the link 11 and the armature 12 may be described as a jack-knife or foldable armature having its centers normally displaced from linear alignment by a small angularity, so that a relatively slight force applied to the free end of the armature 12 will suflice to hold the toggle mechanism D in circuit-closing position, as shown in the diagram, Figure 10.

Such relatively slight force is supplied by the electro-magnet or holding coil 13 when the latter is supplied with energy from the respective line leads 1'7, 17. It follows, therefore, that, when for any reason the supply of current to the electro-magnet 13 is interrupted, the armature 12 will be free to fly up or away from the magnet 13, thus releasing the toggle mechanism D and permitting the spring-set arms 4, 4', to actuate the shaft 2 to, in turn, shift or move the contact-members l of the circuit-breaker C to circuit-opening position or into the position thereof illustrated in Figure 4. Such a condition may arise as on the occurrence of no voltage in either the line or the load side of the circuit-breaker, as is well understood by those skilled in the art. It will also be seen that the armature 12 may yield to the pull of the upset toggle D on the passage through the circuitbreaker of a voltage of less than a predetermined or so-called minimum value, known to those skilled in the art as low voltage conditions.

Again, a push-button 14 or other suitable switching device may be associated with the circuit 13 of the magnet 13 for interrupting the supply of current thereto, thereby causing the cont'actmembers l of the circuit-breaker C to assume circuit-opening position. The push-button 14 may be remotely or otherwise located relatively to the apparatus proper and connected thereto by suitable wires, the switch 14 being normally closed to complete the circuit 13 of the magnet 13. The switch 14, however, may be manually manipulated to open said circuit and thereby tie-energize the holding magnet 13, thus furnishing a so-called remote-control means for actuating the circuit breaker proper C to disconnect the circuit-line side B from the circuitload side B thereof.

A further switching means E, hereinafter referred to as the over-load relay, is inserted in the circuit of the magnet 13 for interrupting the supply of current thereto as on the occasion of an "over-load current through the circuitbreaker C, that is to say, on the passage therethrough of a current greater than a predetermined amperage.

In a protective circuit designed to operate against over-load conditions, the time element of the rupture of the circuit is of prime importance, particularly so with respect to alternatingcurrent breakers. ing-current frequencies vary from twenty-five to sixty cycles per second. It is preferable that, on the occurrence of an overload condition, as. for example, a short circuit, the protected circuit be interrupted before the expiration of any remaining half-cycle in which the short occurs. In the present apparatus, this object is accomplished in the following manner:

The over-load relay E includes a plurality oi relay coils or magnets 15, 15, there being two such coils now shown, although more or less may be employed according to the requirements of the circuit to be protected. Each of the respective coils 15, in the present instance, is connected by leads 19 across a shunt F, more par- 18. connected-inseries with each other and with the circuit 13? of the holding coil 13. The latter isconnectedcacross the line, while the relay-coils are connected in serieswith the line; it follows, therefore, that, when an overload or-short circuit occurs in the load side B of the protected circuit, therelay coils 15, 15, are either or both influenced by suchabnormal overload condition in the protected circuit to open the circuit 13 of the holding coil 13 by actuation of the respective armatures 18, thus releasing armature 12 as the holding-0011 13 isde-energized, the release of the armature 12 being hastened by means of a so-called kick-oil or tripper-arm iS actuated by the armatures 18, as more fully later appears.

The operating time-factor involved in this portion of thecircuit A is thus limited, practically, to the electrical lag-factor of the relay-coils 15 plus the mechanical lag-factor of the relayswitches 18. By proper design, this operating time-factor may be made very small indeed, and

when employed in connection with the circuitbreaker proper, presently to be described, I have found that the foregoing protective circuit and its associated coacting mechanisms will provide a rupturing time-interval closely approximating .002 to .003 seconds, depending upon the point in the voltage wave at which the overload occurs.

Nothing anywhere near thistime-element has been obtained with ordinary alternating-current circuit breakers, so far as I am aware, and about the best performance that has been recorded, so far as I know, and as I have stated,is .016 seconds for the rupturing time of the circuit. It will be seen, thereforathat I am able to rupture an ordinary sixty-cycle alternating current well within the time limit of one-half an alternation thereof. i

In some circuits to which my invention is otherwise adapted to afford adequate protection, it is desirable to introduce a so-called time-delay device, as the rapidity oi my apparatus is such that the circuit might be opened on momentary overloads having such a short duration as to be practically negligible so far as damage to the protected circuit is concerned. In such cases,

the shunts F are preferably constructed in ac-- cordance with the time-delay device fully described in my -co-pending application filed April 5, 1928, Serial Number 267,787, to which reference is made.

Briefly, it maybe now stated, each of such tablished, but the current flowing through ele-- ment 16, due to its positive temperature coefiicient characteristic varies as the total current flowing; and its resistance changes with its temperature so that any desired time delay may be designed due to theflux change brought aboutin ture changes.

previously referred to as the sett' the associated relay coil. circuit 19, that is to say, a change in resistance of element 16 is a constantly varying function due both to the varia tions in main line current and its own tempera- In connection with the remote-control switch 14 for distantly controlling the circuit-breaker to open its protected circuit, means is provided for remotely contr the setting mechanism of the circuit-brea including a setting lever 20, which may be also 'rnanualiy operable, o eratively associated with the line leads i7, 17, the circuit 21' of the electromagr 21 including a distantly located pushbutton or like switching means 22, normally in open position, but adapted for manual manipulation to energize magnet 21 for actuation of the setting lever to close the circuit breaker, in a manner presently appearing.

To clearly illustrate the electrical circuit as hereinbefore set forth, the same is diagrannned in Figurei); divested of its associated mechanical mechanism, except that InC-Chs-d form of timedelay device F is shown, the same being charcterized employ lg a supplementary switching coil 199 series with the circuit 19, and operatively associated with a switch 102 connected in series with the res ice element 16, for a purpose presently appea Attention is directed to the relative simplicity of the circuits shown, in View of the protection ded, inasmuch as the protected circuit repre ented by the line wires B and load B protected against overload, low-voltage, amino-voltage conditions entlrely by the one circuitbreaker, when employed in connection with the associated protective circult A. So far as I am aware, all novoltage mechanisms at the present time operate to hold a spring in tension, which when released, due to failure of the voltage, a plunger to release a trigger, whereby the breaker may then be actuated to circuit-opening position. The overload means on present circuit-breakers is a separateiy attached'arinature co-operating with the trigger for releasing ctuation thereof, but there is no association functions between the no-load and over-load protective means in present breakers. inherently provides low voltage protection by the same means for securing over cad protection.

, The mechanism associated n the protective circuit A is more fully illustrated in Figures 1 to 8, inclusive, and will now be described in detail.

The toggle mechanism D includes the lever 20, g lever, which is pivoted intermediate its ends, as at 23, to and upon a pair of bracket-members 24 mounted on a base 25, the latter beingshown as it would usually appear on a vertically disposed switch-board panel (not shown), although the apparatus will be operative in other positions and locations, as may appear best for the purposes intended.

he toggle-arms 9, which provide a link-connection, are disposed parallelism upon opposite sides of, and coniointly pivoted at an end, as at 26, to, the inner end of the lever 29; and having a per, means preferably In my invention, thev protective circuit,

portion disposed between and pivotally connected Upon their rear or upper edge and adjacenttheir lowerend, the arms 9are provided with a with the upper rearward edge portion of the arm 10. Thus the co-operating abutting portions of the arms 9, 10, form what may be described as a rule-Joint therebetween, limiting the forward or downward pivoted movement of said arms at the pivot 27, with the result that the arms 9, 10, are adapted to fold rearwardly or upwardly to actuate the crank arm 5 and thereby partially rotate or rock the main shaft 2 for, in turn, swingably actuating the contact-members 1 of the circuitbreaker C for effecting opening or breaking of the circuit protected thereby, it being evident that on reverse actuation of the shaft 2 on forward or downward folding of the toggle-arms 9, 10, at the joint or pivot-point 27, the contact-members 1 will be correspondingly swingably actuated into co-operatlve engagement to close the protected circuit. It may be here stated that the lever 20 is provided, at its outer end, for ready and convenient manual manipulation, with a preferably insulation handle 32.

When the toggle-mechanism D is fully extended, as in Figure 1, the lever 20 normally inclines at its handle-end rearwardly or upwardly (reference being had to Figure 1) and at its then lower or forward end engages a stop-pin 42 threaded for adjustment on the forward side of one of the bracket-members 24, the crank-arm or cam 5 being then in position corresponding to circuit-closing position of the shaft 2 with respect to the contact-members 1 of the circuitbreaker C. When so extended, it will be noted. particularly with reference to Figure 1, that the hinge-joint 27 is slightly offset towards the rear of the linear direction of the pivot points 26, 27a, that is to say. the toggle is cracked, so to speak, and is, therefore, normally freely movable to circuit-opening position. lHence, rearward or upward folding or flexing of the toggle mechanism would, unless restrained, occur at the hingejoint 2'7; on the other hand, forward or downward flexing movement of the toggle at the joint 37 is limited by the co-operating action of the linkll and armature 12 as they approach linear alignment, the link 11 being pivotally connected at one end to the knuckle-joint 2'7, and at its other end, as at 33, to the relatively distant free end of the swingable suitably elongated armature 12 electromagnetically associated with the hold ing-coil or magnet 13. At its other or near end, the armature 12 is pivotally supported, as at 34, upon a bracket 35 projecting from the base 25,

the bracket 35 also preferably serving, as shown,

to support one end of the coil 13.

when the magnet 13 is excited, as in the manner hereinbefore set forth, the magnetomotive forces set up by said excitation tend to attract the free end of the armature 12, the force of the pull, of course, being determined by the inductive value of the holding-coil winding and the nature and size of the armature 12. This pull of the magnet 13 resists the tendency of the toggle arms 9, 10, tnfold rearwardly or upwardly, which folding action, when it occurs, lifts or shifts the free end of the armature 12 away from the adjacent polepiece of the magnet 13 by reason of the link connection 11 between the armature 12 and the knuckle-joint 27.

The armature 12, in co-operation with the link 11, forms what may be described as a "jackknife armature, normally arranged so that the lever-arm of the magnetic forces of the coil 13, ae applied to the free end of the armature 12,

is much greater than the lever arm of the mechanical forces, represented by the off-set toggle arms 9, 10, which form, as I have stated, what may be described as a cracked toggle, tending to oppose the pull of the magnet 13. Hence a relatively very small pull or attraction of the magnet 13 for the armature 12 will eifectually resist a relatively very great pull or force exerted by the folding tendency of the toggle mechanism D, the latter being urged towards folding movement by a mechanism now to be described.

Co-operatively associated with the cam-lever 5, is the arm 4 fixed on the shaft 3 journaled in brackets 36 mounted on the base 25. Other arms 4' may also be fixed on the shaft 3, there being one arm 4 shown in the present embodiment, which arms 4, 4', co-act through the shaft 3 and cam-lever 5 to normally rotate the shaft 2 for actuation of the circuit-breaker C to circuit-opening position.

Springs or tensional members 37, 37' are mounted on plungers 38, 38, respectively co-opcrating with the arms 4, 4, the plungers 38, 38', each being shiftably mounted, preferably through the base plate 25. Nuts 39, 39', respectively, mounted on the plungers 33, 38, limit the springurged movement of the plungers 38, 38, as by engaging, in the present instance, the rear side of the base-plate 25. The nuts 39, 39 may be screwed into or out of the respective plungers 38, 38', to adjustably impinge the plate 25 on said movement of the plungers, so that one plunger, as 38, will be brought to rest before the other, as 38, for a purpose presently appearing.

Preferably the tensional members 37, 3'7, are of the compressive type and, while complcsced when the contact-members 1 are in circuit-closing position, constantly exert their tension, through the co-operating arm 4 and cam 5, to rock the shaft 2 to actuate or shift the contact-members 1 to circuit-opening position. For varying or adjusting the initial spring tension of the arm 4 on the cam-lever 5, set-screws 40 may be provided, threaded through the respective arms 4, 4', for impingement on plunger-heads 41 on each 120 of the plungers 38, 38, said plunger-heads ll also abutting the outer ends of the respective tensional members 37, 37, whose inner ends, in the present instance, abut the base 25.

' It is of prime importance that, wlicn necessity 25 arises for opening the circuit-breaker C, the actuation thereof will take place in the shortest possible operating time-interval, as hcreinbefore set forth in describing the circuit A. In such description, it was pointed out how the electrical- 3 time-lag has been, by my present arrangement, reduced to a very low figure indeed, and it may here be pointed out that the several co-acting mechanical parts of the circuit A, just described,

are likewise characterized by a relatively low me- 135 chanical-time-lag, as presently appearing, and I may also state that the reason I prefer to employ my circuit-breaker C is that the same embodies like characteristics of extremely rapid action, all

of which will be more particularly set forth the 140 description proceeds.

To reduce to approximately the smallest possible extent the operative time-lag of the mechanical structure associated with the electrical circuit A, I have arranged and constructed the 145 several co-acting parts of the toggle mechanism and associated elements so that those parts that have the greatest amplitude of movement are of the lightest weight because they are subject to the least stresses. On the other hand, those parts 150 which carry the heaviest stresses, and which must correspondingly be of theheaviest and strongest construction, have the least amplitude of movement. The result is that the acceleration constant of the several elements is of approximately like value throughout.

The several parts are furthermore constructed in a multiplying ratio, such that the forces tending to move any one of the elements are of lesser degree the lighter the part. Hencethe energyconstant ofv the co-operating several parts, as presently appearing, is approximately of like value throughout the mechanism.

More particularly, the springs 37, 37, are relatively very heavy and strong, and they. are preferably constructed to exert their designed extensile force Within a small extension of the spring. The lever arm of the springs 37, 37 with respect to the shaft 3'is less than the leverarm of the engagement of the arm 4 with the camlever 5 with respect to the shaft 3, and the latter lever-arm is greater than the lever arm of the cam-lever 5 with respect to the shaft 2. Thus the angular movement of the shaft 2 is greater than the like movement of the shaft 3, that is to say, the throw of the cam or crank 5 is multiplied over the throw of the levers 4, 4'.

The lever-arm of the force applied through the crank 5 on the toggle arms 9, 10, with respect to the pivot point or knuckle-joint27 is less than the lever-arm of the crank 5 with respect to the shaft 2. From this arrangement, it will be readily seen that but a very small force applied to the knuckle-joint 27 will effectually resist the relatively great shaft-rocking force of the springs lag may be made very small indeed, and I have found that an operative time-cycle of aboutfJGZ to .003 seconds may be obtained when the toggle mechanism is employed in connection with the electrical circuit A and my circuit-breaker, as presently appearing. i

As fully set forth in connection with the description of the circuit A, the excitation of the magnet 13 may be lessened or discontinued on the occurrence of an abnormal condition in the protected circuit associated with the circuit-breaker I impinges the pole piece 66 of the coil 7 by means of which the entire mechanism may be brought to rest, the handle end 32 of the lever 20 drop-v ping downwardly to take an inclined position, for a purpose soon to appear.

While the mechanism may be brought to rest as described, it is desirable that the parts be decelerated during the terminal portions of their respective movements. For this purpose, the nuts 39, 39 are adjusted with respect to their respective plungers 38, 38, so that the pressure of the springs 37, 37', applied through said plungers:

on the arms4, 4', will be effective on the shaft 3,

during the acceleration of the toggle mechanism; after the parts are accelerated to the desired speed, one spring, as 37, will become inoperative because of the impingement oi the nut 39 with the base 25 to limit the movement of the plunger 38, as hereinbefore described. The remaining spring, 37, continues effective for operative movement of the shaft 3 for another portion of its movement, but the spring 37' is in like manner rendered i operative before the completion of the actuation of the circuit-breaker, so that, since there is no ion, 1' any motivating force. to actuate the to thereof natur lose their momentum, and the system nds to come to rest about the time the arm 4 .pinges the pol piece 66.

The forog ing description of the operation of the toggle-mechanism applies to the movements taking place on any abnormal condition of the protected circuit, but there is an additional protective means which comes into action on the occurrence of an over-load in the circuit, which may, for example, be occasioned by a short-circuit. In the case of overload conditions in the controlled circuit, particularly in an alternating current circuit, the speed of rupture of the circuit should be commensurable with the overload value of the current thereof. When this speed of rupture is effected, a short-circuit, as'such,does notexist, and-the strain on the line is rather'of a character classed as amomentary heavy overload.

To accomplish this purpose, two means are provided, one of which will be presently described in connection with the over-load switches 18, 18' the other means includes the series coils 7, connected in the load side of the line as hereinbefore i set forth, magnetically associated with the arms 6 fixed on the shaft 3, which arms 6 may, and in the present instance are, associated with the arms 4, 4", respectively,valthougn this is a matter of convenience. These series coils 7 e'xertan attractive force on the arms 6, which, being.

transmitted to the shaft 3, are in additiveaccelerating relation to the tensile force of the springs 37, 37', for the actuation of the'circuitbreaker to circuit opening position.

This additive actuating effect exists, of course, whenever there is a flow of current through the circuit-breaker, but is particularly effective on the occasion of line surges, such as may, for example, be caused by a short-circuit in the line. The momentary heavy flow of current occasioned by a short-circuit or other overload or like character greatly increases the pull of the magnets 7, 1 '7, and effectually augments the actuating forceof the springs 37, 37, during the accelerating pe riod of the movement of the toggle-mechanism,

during which time, usually, the line circuit is opened or interrupted. However, no circuit rup-' turing movement of the breaker C'may take place until the magneto-motive force of the holding coil'or magnet 13 has either been reduced below a predetermined point, as on low voltage conditions, or until the supply of current to the magnet 13 has been interrupted, by a means now to be glc .mechanism, the. several parts dwcribed, and certain mechanical functions for increasing the operative speed of the device under overload conditions in the protected circuit.

Each switch 18 preferably comprises a lever constructed of magnetic material pivoted intermediatelyits ends on one of the standards 43 in magnetically co-operative relationship with the respective magnets 15, 15. Mounted on each switch lever 18, is an insulated contact terminal 44, engageable with a co-operating contact-terminal or switch-point 45 insulated preferably on the other one of the standards 43. A spring 46 n adiustably mounted on one of the standards 4! why a screw or like member 47 threaded thereto and attached to one end of said spring, the other end of the spring 46 being attached to the adjacent end of the switch lever or armature 18 for normally causing the same to yieldably contact the terminals 44, 45. On growth of a magneto-motive force, as may be occasioned by an overload condition in one of the phases of the line, or greater than a predetermined value in the respective coils 15, 15, the associated switch member 18 will be actuated against the tension of the respective spring 46 to separate the terminals 44, 45, associated with the particular coil 15 connected with the phase in which the overload condition exists.

As has been previously described, the switching members 18 control the circuit 13' of the holding-coil 13 for interrupting the same. Such an interruption of the circuit 13', as will be understood, de-energizes the magnet 13 and releases the armature 12 for circuit-opening movement of the circuit-breaker C, this being the electrical function of the said switches 18.

Pivoted at one end to one of the standards 43, isa tripper-arm 48 provided at its other end with 1!. lug 49. Links 50, are each pivotally connected at one end to the respective switching levers M 18; the other end of each of the links 50, 50'

1:0 more rapid flexing of the toggle arms 9, 10. This has a pin 51 working in respective slots 52 in the free end of the tripper arm 48, the lug 49 being normally disengaged from, but adapted on swinging movement of the arm 48 to impinge on, the free end of the armature 12 for lifting or shifting the same away from the magnet 13.

As seen in Figure 1, the switch levers 18 move outwardly for disengagement of the respective DI-irs of terminals 44, 45. The link 50 connected to the outermost of the levers 18 is normally disposed so that its pin 51 will impinge the outer end of the co-operating slot 52 in the arm 48; the link 51 connected to the inner lever 18 likewise normally impinges the outer end of its co-operating slot 52. Hence the tripper arm 48 may be actuated for lifting or shifting movement of the armature 12 by either of the levers 18; when the latter are, in tum, magnetically actuated by their ,respective over-load coils 15, 15. The result is that, on the occasion of an abnormal or overload condition in the line, the tripper arm 48 will impinge the armature 12 to effect what may be described as a kiclboi'f or preliminary acceleration to the armature 12 to off-set whatever residual magnetism may exist in the magnet 13 after its circuit 13' has been ruptured by the contact disengaging movement of the respective lovers 18, and also to speed the armature 12 in unfolding movement of the link 11, to permit the efl'ect constitutes the mechanical functions of the over-load switches 18, 18, which, it will be observed, thus co-operate with the electrical functions hereinbefore described.

An additional protective feature is supplied by the electric circuit A and its associated mechanism D, which may be described as a means for rendering the circuit-breaker trip-free, that is to say, the circuit-breaker C may not be retained in closed position by manipulation of the lever 20 unless the abnormal conditions in the line, assuming that such have had the eil'ect of actuating the apparatus to open the circuit-breaker, no longer exist.

This trip-free protective feature, best seen in Figure 3, is associated with the manner in which the setting lever 20 acts to reset the toggle arms 9, 10, in extended position after flexure or folding thereof. First it will be noted that the toggle arms 9 have a certain possible amplitude of uscillation about their pivot point 26, in other words, fiexure or folding of the toggle arms 9, 10, from the position shown by full line. In Figure 1, may occur while the setting-lever 20 rests against the adjusting screw 42, and I may here state that, when the setting lever 20 rests against the screw 42, it is held thereagainst by the forces acting through the toggle arms 9, 10, that is to say, the lever 20 is oscillatable past its momentary dead center with respect to the linear alignment of the toggle arms 9, 10, so that when in circuit closing position, the inner end of the lever 20 is below said linear alignment of the toggle arms;

To open the circuit-breaker C by means of the lever 20, the latter must be manipulated so as to swing its inner end rearwardly or upwardly, such movement, of course, releasing the toggle arms 9, 10, for flexing movement.

01' course, when the link and lever arrangement thus established by the coaction oi the lever 20 and toggle arms 9, 10, has passed its deadcenter in circuit-opening movement, the springs 37, 3'7, come into play and cause a quick, snapping movement of the mechanism, as described. In fact, all that is necessary to manually open the breaker is to give a push, so to speak, to the lever 20, the completion of the circuit opening movement being accomplished automatically as hereinbefore described, the toggle arms 9, 10, flexing with the hinge-joint 27 ofiset rearwardly or upwardly of the linear direction of the pivot points 27, 27', while at the same time, the lever 20, being thus released from any restraining influence, freely swings so as to move the pivot point 27 away from the pivot point 27a sufficiently to permit the toggle arms 9, 10, to drop into extended position with the hinge joint 27 now offset forwardly or downwardly with respect to the end pivot points 26, 27a, as indicated by the dot-dash lines in Figure 1.

Hence, to again close the circuit-breaker, the lever 20 must be moved in reverse direction to that just set forth, whereupon the toggle-arms 9, 10, act as an inflexible link to rotate the shaft 2 to circuit-closing position, until the link and lever arrangement recrosses its dead center, when the toggle arms 9 will be slightly flexed with respect to the arm 10, the lever 20 at the same time impinging the stop-screw 42, and the several parts reassuming their normal circuitclosing positions.

In the meantime, while the foregoing action has taken place, the armature 12, through the link 11, has been dropped upon the pole piece 1 of the magnet 13, there to be retained provided the magnet is sufiiciently energized when the circuit is established through the breaker C.

Now it is to be pointed out that, while the setting lever 20 has been moved to setting position and may be held there manually or otherwise, as will presently appear, nevertheless the toggle mechanism B may be tripped for opei ing the tion exists in the protected circuit, as will be readily seen from Figure 3, wherein is shown a momentary position taken by the several parts when, an example, an overload exists in the protected circuit. It will be understood from the foregoing description that the movement of the toggle that the toggle may be fully flexed before the handle 20 has startedtc drop, and, furthermore, before the levers 18 have dropped away'from the coils 15. This is the condition shown in Figure 3, and from an examination of this figure it will be seen how the breaker C may be fully opened while the handle 20 is in circuit-closing that is to the toggle is actuable to circuitopening position on interruption of its magnetic association with the holding coil 13 independently of the manually operable lever 20.

Consequently the toggle mechanism D is fully tripefree, while the circuit-breaker C may be momentarily closed, it will not remain so unless the line conditions are normal. This fact will be readily understood. with respect to novoltage or low-voltage conditions in the line, since then there will not be suflicient pull exerted by the magnet 13 to offset the forces tending to flex the toggle; it will also be seen that an overload condition in the line will cause one or the other, or both, of the switching levers 13 to be held in position for opening the circuit 13 of the holding coil 13.

of ov rload conditions in the line, the tri ping arm serves the useful function, under the conditions desc ed, of engaging the armature 12 while th latter is yet in a position corresponding to a considerable angular displacement of the same with respect to the link 11 when the toggle mechanism has resumed its circuitclcsing position. The pull of the forces tending to the tog le mechanism D is, therefore, under these cond ions, much more effective in lil mg the armature 12 away from the magnet 13 for actuating the contact-members l of the circuit-breaker to circuit opening position.

The electrically operable leans, or so-called remote control, for closing the circuit-breaker C through the toggle-mechanism D includes, as

I ha e heretofore outlined, the solenoid 21, electrically connected as described, magnetically as sociated with a swingable arm 53 connected'by link arrangement 54 with an intermediately multiplying lever 55, one end of the lever'55 being pivoted to one end of a radius arm 56 whose other end pivoted to the pivot center 23, and the other end of the lever 55 beingpivoted to one end of a link 5? whose other end in turn, pivoted to setting lever 20 preferably at the pivot point 26. Hence a relatively small movement of the arm 53 will swing the setting lever 20 sufliciently to move the same to circuit closing position, such. movement being accomplished by pres. ng the push button 22 for closing the solenoid circuit 21', as hereinbefore described.

The manner in which the toggle mechanism D may be manually moved to circuit opening position having described, it remains to be stated that same action takes place when the toggle-mechanism is automatically Hence it follows that. whether the circuitbeen armsl9, if), is very rapid, so much so breaker is manually opened or automatically tripped, the succeeding position of the lever 20 is in its circuit-opening position, that is to say, with the handle-end 32 thereof inclined downwardly, from which position, in the manner heretofore set forth, the lever 20 is moved upwardly to close the circuit-breaker.

In order to nicely adjust the location of the pole piece (-31 of the magnet 13 with respect to the desired operative position of the armature 12 and link 11, the pole piece 61 is provided with a foot piece 62 normally spaced from the base member 25, the magnet 13, as a whole, being normally supportingly presented from the bracket 35. A certain amount of flexibility of movement or the free end of the magnet 13 is possible, however, and a screw 63, attached to the foot piece 62 and freely passed through the base member 25, is threaded to nuts 64 abutting on the rear side of the base member, by means of which the polepiece 61 may be adjusted relatively to the base member 25, that is to say, inwardlyor outwardly, as may be desired, to change the angularity of the lever 11 with respect to the armature 12 when the latter is resting upon the pole piece 61.

Preferably, as a structural feature that may here be pointed out, the accelerating coils 7 are wound on magnetically permeable cores 66 adjustably supported on the base member 25 by means of screw or like fastening members 67, freely passed through the base 25 for abutting its head, on the rear side thereof, whereby the cores 66 may be nicely adjusted relatively to the arma ture levers 6 for regulating the magneticpull of the coils '7 on armature pieces 68 mounted on the levers 6. Another structural detail is the polepieces 69 of the respective over-load coils 15 for facilitating the magnetic co -operation thereof with the respective levers 18, and it may be here remarked that the power plant of combined springs 3'7, 3'7, and series magnets or coils .7 makes the power exertedto open the contacts a function of the size of the short or overload. The springs 37, 37 are, as I have stated, preferably arranged in cascade setting, so that the last spring is compressed after the first spring has been partially compressed. This arrangement allows for a much easier setting pressure on the to le levers at the beginning of the stroke, as the leverage just before the toggle straightens out is greatly increased and allows of more compression without increase in power exerted.

The protective circuit A and the co-operatively associated toggle mechanism D may be employed in connection with any of the so-called panelboard.circuit-breakers or the like, as suggested in Figure 10, and in such use my invention efficiently performs its intended functions and although I show one preferred form of circuitbraker proper, soon to be described, I do not wish to be limited to such particular application.

A brief description of the preferred form of the circuit-breaker proper will now be given, a full, complete description thereof appearing in my said co-pending application, Serial No.-

3194, 0, certain perfections over the construction there set forth being from time to time pointed out as the present description proceeds.

Referring now more particularly to Figures 2, 4, 5, 6, and 7, the circuit-breaker proper C, in its preferred embodiment, includes a suitable housing G having front and side walls '70 and 71 of suitable contour and constructed preferably of any suitable insulation material, the front wall 70 thereof being preferably removable or detachable for facilitating assembly of parts. The baseplate 25 preferably extends under the housing to form the other or rear wall thereof.

Fixed within the housing G and upon the base 25, is a pair of spaced insulation walls or partitions '72, 73, which are of suitable height and which preferably extend in parallelism with the side walls 71 of the housing to form a plurality of chambers 74, 75, and 76, each chamber being associated with one of the phases of the alternating current circuit, which, in the embodiment shown, the device is adapted to protect or control. A similar construction would also apply to D. C. circuits.

Fixed within each of the chambers '74, 75, and '76, and upon the base 25 common thereto, is a pair of spaced insulation blocks 77, 78, which are of suitable heighth and which preferably extend from side to side of the respective chambers to form therein, between each pair of blocks 77, '78, a plunger well 79 (Figure 4).

Disposed for reciprocatory movement in, and guided in its reciprocations by the walls of, each of the wells 79, is an insulation block or plunger 80, mounted in which is a pin 81 pivotally connected by a link 82 to the outer or free end of a crank or arm 83 fixed at its other end on the main shaft 2, the latter extending through the several walls in the housing and through a suitable shaft chamber 84 provided beneath the respective wells '79. On a rocking or partial rotation of the shaft 2, effected as hereinbefore described, the several blocks are reciprocated in their respective wells 79, preferably all at the same time and with equal amplitude of movement.

Disposed upon the blocks 77, 78, are conducting pieces or terminals 85, 86, and suitably hinged or pivoted, as at 8'7, 87, to the terminals 85, 86, are coacting pairs of the contact-members 1, which are preferably L-or-hook-shaped and presented outwardly in the respective chambers '74, 75, and (6,the members 1 comprising flat strips of conducting material bent laterally in opposing relation at their respective outer or free ends for supporting opposed engageable pole pieces 89, 90. It may be here stated that the contact-members 1, 1, are simultaneously swingable in opposite directions to separate and space the pole pieces 89, 90, to open the circuit, as in Figure 4, or to bring them together into engaging relation to close the circuit, as in Figure 5, the circuit being indicated by the line and load wires 17 and 8, respectively, attached directly or indirectly to the respective terminals 85, 86, by suitable binding screws 91, which latter also may serve in part to secure the terminals 85, 86, upon the respective blocks '77,

78. To obviate arcing at the hinge joints 87 and insure line-connection with the contact-members 1, pigtails 92, 92, suitably also electrically cennect the contact-members 1 with the respective terminals 85, 86.

Fixed upon the contact-members 1, adjacent the hinge-joints 87, are arms 93, and pivoted at their opposite ends to the arms 9'3 and the plunger 80, are links 94, whereby the contact-members 1 are adapted for swingable actuation toward and away from each other as the plunger blocks 80 are caused to respectively move inwardly or outwardly in their respective accommodating wells 79, and it may be here stated that, when the engageable pole pieces or blocks 89, 90, are in electrical circuit-closing engagement, the contact-members 1 are in approximate parallel relationship, as shown in Figure 5, and when the breaker is actuated to open the circuit, the contactmembers l fly apart and are then inclined away from each other, as shown in Figure 4.

Disposed in abutting adjacence to the front wall 70, and transversely through the partitions 72, 73, for engagement with the side walls 71 of the housing, is an insulation block or closure strip provided upon its inner face with a plurality of longitudinal slots 96, each slot 96 being coextensive with and presented with its open side towards the respective chambers 74, 75, 76.

Mounted on each of the plunger blocks 80, and slidably contacting the enclosing walls or partltions of the respective chambers 74, 75, 76, is an outwardly presented shutter wall 97 of insulation material adapted, on outward movement of the block 80, to be siidingly extended with its outer edge into the opposing slot 96 in the closurestrip 95. When so engaging the closure-strip 95, the shutter wall 97 coacts therewith to insulatably divide the respective chambers 74, 75, and '76 into adjacent compartments, each compartment containing one of the contactmembers l, as shown in Figure 4. This outward movement of the plunger block 80 and its carried shutter-wall 97 occurs on circuit-opening movement of the shaft 2, during which movement the contact members 1 fly apart, while the shutter-wall 97 is slidably interposed therebetween, for a purpose presently appearing. But when the plunger block 80 is retracted into its accommodating well 79, on circuit-closing movement of the shaft 2, the shutterwall 97 is disengaged from the slot 96 and correspondingly spaced from the closure-strip 95 a distance suflicient to allow the introduction therebetween of the engageable pole pieces 89, 90, for circuit establishing contact thereof, as shown in Figure 5.

Now, when the breaker is tripped, especially as on an overload, the plunger block 80 suddenly rises, under the influence or tension of the spring or springs 37, 37', or a combination of forces furnished by series coils ('7) and springs 37, 37', or by series coils ('7) acting alone, to its outermost position, the pole pieces 89, 90, are caused to fly widely apart, and the shutter wall 97 correspondly moves outwardly through the respective chambers 74, 75, 76, into engagement with the closure strip 95, as described, and interposes an insulation partition between the contact-members 1 and their carried pole pieces 89, 90, thereby isolating or separating the contact-members 1 and pole pieces 89, 90, the one from the other, and suppressing or breaking any occurring are, while the sudden movement of the plunger 80 generates or creates an air-blowout effecting dissipation or dispersion of the hot gases through the opposite open ends of the housing G.

Inasmuch as the are, commonly growing on the separation of the pole piece 89, 90, is positively suppressed by the insulation wall 97 in co-operation with the insulation strip 95, the contactmembers 1 and pole pieces 89, 90, may be of relatively light construction. Thus the acceleration constant of these parts is likewise relatively small, and the breaker as a whole is characterized by an extreme rapidity of operation, commensurate with like characteristics of the breaker actuating toggle mechanism D and the electrical protective circuit A, as hereinbefore set forth.

The pole pieces 89, 90, of the present breaker are preferably at their engageable ends dis-similar in shape and form, as best seen in Figure 6. Thus the one pole piece, as 89, is provided at its engageable end with a V-shaped groove 98, while to the terminal and when S9, 90, are in circuit-clos- 9 is guidingly fitted into onverging walls thereof,

a lishment of an effective nd, separation or the pole pieces 89, -otected circuit is carrying a curother 90,'wh n the 1 rent at the tune of rupture thereof, the arc normally occurring theebetween is divided into two parts, each growing from the nose 99 to the opposite walls or" the groove 98. Furthermore, on ued separation of the nose from the groove, the gr owth of the arc is suppressed in part as it is drawn towards the opposite edges of i he groove. The ionized air between. the en ageable pole faces co" 'espondingly attenuated the final sup pro on of the arc is acco. shed. by the interp' ition of th insulation wall 97, as described.

e embodiment shown in Figure 4, each reve shunt including resistance piece -s connected between a terminal 86 and a contact block 100, as shown n Figures 2, l, and 5, but in circuits carrying normally heavy currents, the permanently connected shunt 16 makes the armatures l8 sl -ggish on A. C. current due to. the increased self-inductance of the magnets 15 as the a ature l8 closes the air gap of the pole iece 69. In the modified form of time-delay device F, the block 100 is replaced by a frame 101, and mounted for swingable actuation there on an armature 102 carrying a contact 103 normall' engaging a fixed contact 104 connected 91 by a suitable conductor 105. The contact is connected by a suitable pigtail 106 to one terminal 107 of the resistance element whose other terminal 108 is connected to the line 17. Magnetically co-operatingwith the armature 102 an electromagnet 109 connected on one side to one end of the circuit 19 of the coil 15, the other end of said circuit being connected to the terminal 108. The other side of the coil 109 is connected tothe terminal 91.

By referring to Figure '11, it will be seen that the contacts 103, 104 are normally engaged in series with the'element 15, but on occurrence'of an overload in the line i9,the armature 102 is at tracted by the coil 109 with. sufiicient force to separate the contacts 103, 104, thus breaking the circuit through the element 16 and causing all current to flow through the coil 16. No are results, however, the coil is normally in p rallel w the circuit through the element 16, latter circuit is broken thecurrent 1S s1 oly dd J1 :ted through the coil 15, this condition continuing as long as a current of sulficient strength is flowing through the coil 109. Ey th s arrangement, the setting of the device eve oads may be most accurately determined, inasmuch, as the suddenly increased flow of current ough the coil 15 offsets the said sluggishness oi. the armature 18.

Tl associated parts well adapted to-answer all renenfs and which most efficiently accomthe objects stated and performs its, in-

' TlCtlOl'lS. Under the influence of the contacts at time of break is accomplished, as

I provide a circuit-breaker proper and the spring travel of the one spring is reduced many times and its power increased accordingly, so that the increased contact speed is proportional to the movements of the two means of actuating the contacts. Ratios of :1 or more are easily obtainable between the break distance between contacts and the main spring movement. in other words, by means of this construction the ordinary methods employed to separate the contacts has been enormously up. It is obvious that the series coil (7) referred to in the foregoing may be so designed as to dispense with 0221C! power zr ns, such as springs 37, 37, to actuate the circ breaker to circuit opening position on the occurrence of an overload or short circuit condition.

Further, the p cnt apparatus, by toggle release for ten ion in direction of operation, time is I 1060 to its lowest possible element, series armature movement is reduced to its lowest possible element, and contact separation speeded up to the highest practical speed.

From other standpoints, thi apparatus offers the solution for breaking high voltage currents in air without the aid of blow out coils, arcing horns, or other cumbersome means. Positive break is assured by the compartment arrange roent, and the crank shaft operating link mecha- A breaker built according to my invention eliminates short circuits in the accepted terms and substitutes what may be classed as momentary heavy overloads.

Among other structtu'al features of special importance that might be mentioned are- The compartment arrangement for the contact-members, which oiiers the singular advantage of not having any structural or frame parts in compartment to furnish a means for the current to short between phases or to ground, especially valuable in high tension breakers.

The design of the contacts, male and female, and easily renewable the double line contact obtained not only increasing the carrying capacity of the contacts, but also introducing a double air break when ruptured, of twice the resistance of a single line contact.

The restoring movement of the toggle levers,

which does away with other means for bringing this linkage into position after tripping.

The co-operation of the time-delay device with the cracked toggle mechanism, which effectively protects the associated circuit, yet avoids unnecessary rupturing thereof.

The automatic low voltage protection furnished on failure of voltage, the breaker requiring for restoration to closed position actuation either manually or through the remote control setting button. The remote operation is handled by a normally closed momentary contact button and a normally open momentary contact button. The first for opening the circuit, and the second for restoring the circuit. Manual means is provided for either operation.

The means for making the overload or short circuit current surge actually perform work in opening the circuit-breaker, which work is done irrespective of the forces exerted by the springset actuating means.

The estimated rupturing time of the apparatus with the combined magnetic and mechanical power actuating mechanism shown lies between .002 and .003 seconds, depending on the point of occurrence of the short with reference to the voltage wave. This performance is obtained without undue strain on the parts of the mechanism due to the feature of the design which stops the actuating force well before the end of the stroke. This feature also allows the linkage to be restored to a position for setting principally through its momentum assisted by a light spring.

It is to be understood that changes and modiflcations in the form, construction, arrangement, and combination of the several parts of the circult-breaker and its associated instrumentalities may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An electric circuit interrupting apparatus comprising, in combination, a pair of co-operable pivoted contact-members adapted for swingable actuation into and out of engagement for respectively closing and opening the circuit, and means for swingably actuating the contact-members, said means including a shiftable block, links having pivoted connection with the block and contact-members, and a rockable block-shifting shaft.

2. An electric circuit interrupting apparatus comprising, in combination, a pair of co-operable pivoted contact-members adapted for swingable actuation into and out of engagement for respectively closing and opening the circuit, means including a shiftable block having pivoted link connection with the contact-members and a rocltable block-shift shaft for swingably actuating the contact-members, and means for yieldingly rocking the shaft for swingably actuating the contact-members into normal circuit-opening position.

3. An electric circuit interrupting apparatus comprising, in combination, a pair of co-operable pivoted contact-members adapted for swingable actuation into and out of engagement for respectively closing and opening the circuit, means including a shiftable block having pivoted link connection with the contact-members and a rockable block-shifting shaft for swingably actuatlng the contact-members, a crank-arm fixed on the shaft, and means including a springpressed arm having engagement with the crankarm for yieldingly rocking the shaft for actuating the contact-members into normal circuit opening position.

4. An electric circuit interrupting apparatus comprising, in combination, co operable swingable contact-members adapted for actuation into and out of engagement for respectively closing and opening the circuit, and means including a series of extensile members having different degrees of extension for yieldingly actuating the contact-members into normal circuit-opening position.

5. An electric circuit interrupting apparatus comprising, in combination, co-operable contactmembers adapted for actuation into and out of engagement for respectively closing and opening the circuit, and means for actuating the contactmembers into normal circuit opening position, said means including a rockable shaft, a cam-arm fixed on the shaft, a second rockable shaft, arms flared on the second shaft, one of said arms havingengagement with the cam-arm, and a series of. extensile springs of dilferent degrees of expansion having rocking engagement through said arms with the second shaft.

6. In combination with an electric circuithreaker comprising co-operable swingable contact-members adapted for actuation into and out of engagement for respectively closing and opening the circuit, an operating meal s for the contact-members, and an actuating means for the operating means, the actuating means including a series of extensile members supplying a motivating force for the actuation of the operating means, said extensile members having different degrees of extension, whereby said motivating force is successively diminished with increase of acceleration of said operating means, said motivating force terminating prior to the completion of the operative movement of the operating means.

7. An electric circuit interrupting apparatus comprising, in combination with a circuit-breaker and its circuit, the circuit-breaker including cooperable contact-members adapted for actuation into and out of engagement for respectively closing and opening the circuit, mechanical means for actuating the contact-members, and electrically responsive means included in the circuit for accelerating opening actuation of the contactmembers on an abnormal condition occurring in the circuit.

8. An electric circuit interrupting apparatus comprising, in combination with a circuit-breaker and its circuit, the circuit-breaker including co-operable contact-members adapted for actuation into and out of engagement for respectively closing and opening the circuit, means including a rockable shaft for actuating the contact-members, means for yieldingly rocking the shaft for actuating the contact-members into normal circuit-opening position, and electrically responsive means included in the circuit for supplying an accelerating shaft rocking force until the circuit is opened.

9. An electric circuit interrupting apparatus comprising a circuit-breaker and its circuit, the circuit-breaker including cooperable contact- Inembers adapted for actuation into and out of engagement for respectively closing and opening the circuit, in combination with means including a rockable shaft for actuating the contactmembers, a cam-arm fixed on the shaft, a second rockable shaft, an arm fixed in the second shaft having actuating engagement with the cam-arm, mechanical means for yieldingly rocking the second shaft for actuating the contact-members into normal circuit-opening position, and means including a magnet-coil in series with the circuit for accelerating rocking circuit-opening movement of the second shaft on an abnormal condition arising in the circuit.

10. In combination with an electric circuitbreaker and its circuit, the circuit-breaker comprising co-operable contact-members adapted for actuation into and out of engagement for respectively closing and opening the circuit, an operating means for the contact-members, an actuating means for the operating means, the actuating means including a plurality of extcniile members supplying a motivating force for the actuation of the operating means, said extcnsilc members having different degrees of extension, whereby said motivating force is successively dilib minished with increase of acceleration of said operating means, said motivating force terminating prior to the completion of the operative movement of the operating means, and means electrically responsive to flow of current in the circuit having magnetic association co-operative- 5 ly with said operating means in additive effect to said motivating force for supplying an accelerating force to said operating means until the circuit is opened.

11. In an electric circuit interrupting apparatus, in combination with a circuit breaker and its circuit, the circuit-breaker comprising co-operable contact-members adapted for actuation into and out of engagement for respectively closing and opening the circuit, mechanical means including a toggle adaptedfor folding actuation for moving the contact-members to open the circuit, and means included and electrically responsive to flow of current in the circuit having magnetic association with the toggle for holding the same against folding actuation on flow of a current of a predetermined value in the circuit.

12. In an electric circuit interrupting apparatus, in combination with a circuit-breaker and its circuit, the circuit-breaker comprising co-operable swingable contact-members adapted for actuation into and out of engagement for respectively closing and opening the circuit, means including a toggle adapted for folding actuation for moving the contact-members to open the circuit,'means adapted for normally eilecting folding actuation of the toggle, and means electrically associated with the circuit and mag netically associated with the toggle for resisting said toggle folding means onflow of normal current for maintaining a closed circuit at the contact-members, said last-namedf means including a magnet coil, an armature for the coil,

and link-connection between the armature and the toggle. I

13. Inan electric circuit interrupting apparatus, in combination with acircuit-breaker and its circuit, the circuit-breaker comprising co-operable swingable contact-members adapted for actuation into and out of engagement for respectively closing and opening the circuit, means including a'toggle adapted for folding actuation for moving the contact-members to open the circuit, means adapted for normally effecting folding actuation of the toggle, and means electrically associated with the circuit and magnetically associated with the toggle for resisting said toggle folding means on flow of normal current for maintaining a closed circuit at the contact-members, said last-named means including a magnet coil, an armature for the coil pivoted at an end with relation to the coil, and a link connection having pivoted engagement with the opposite end of the armature and with the toggle.

14. In an electric circuit interrupting apparatus, in combination with a circuit-breaker and its circuit, operating means for opening the circuit-breaker, actuatingmeans for the operating means including a toggle adapted for folding actuation to open the circuit-breaker, manually operable means co-operating with the. toggle for extension of the same for closing the circuitbreaker, and means included, and electrically I responsive to flow of current in the circuit, having magnetic association with the toggle for holding the same against folding actuation on flow of a ,current of greater than a minimum value, said toggle being actuable to circuit-opening position oninterruption of said magnetic associationindependently of the position of said manually operable means.

15. In apparatus of the class described, in combination, an electrical circuit including switching mechanism operable for opening and closing the circuit, and actuating mechanism for the switching, mechanism including means in series with, and responsive to flow of current in, the circuit for biasing the switching mechanism in circuit opening direction. I V

16. In apparatus of the class described, incombination, an electrical circuit including switching mechanism operable for opening and closing the circuit, actuating mechanism for the switching mechanism including means in series with, and responsive to flow of current in, the circuit for biasing the switching mechanism in circuit opening direction, and means for releasably restraining the actuating mechanism against the bias of the current-responsive means. 17. In apparatus of the class described, in combination, an electrical circuit including switching mechanism operable for opening and closing the circuit, actuating mechanism for the switching mechanism including means influenced for'normally' biasing the switching mechanism in circuit opening direction, and means for removing the influence of the biasing means during circuit-opening operationof the switching mechanism. 1 V

18. In apparatus of the class described, in combination, an electricalcircuit including switching mechanism operable for opening and closing the circuit, actuating mechanism for the switching mechanism including a shiftable plunger infiuenced for normally biasing the switching mechanism in circuit opening direction, and a stop engageable by the plunger during circuitopening operation of the switching mechanism for removing the biasing-influence of said plunger prior to completion of said operation.

19. In apparatus of the class described; in combination, an electrical circuit including switching mechanism for opening and closing the circuit, and operating mechanism for the switching mechanism including a foldable toggle normally biased toward folded position for operation of the switching mechanism to circuit-opening position, said toggle having a rule-joint for extension of the toggle from folded to rigid position for effecting operation of the switching mechanism to circuit-closing position.

20. In apparatus of the class described, in combination, an electrical circuit including switching mechanismfor opening and closing the circuit, operating mechanism including a foldahle toggle normally biasedtoward folded-position for operation of the switching mechanism to circuit opening position, said toggle having a rule-joint for extension of the toggle from folded to rigid position for efiectingoperation of the switching mechanism to circuit-closing position, means for flexing the rule-joint as the switching mechanism attains circuit-closing position, and means for releasably holding the flexed toggle against folding actuation for sustaining the switching mechanism in circuit-closing position.

21. In apparatus of the class described, in combination, an electrical circuit including switching mechanism for opening and closing the circuit, operating mechanism including a foldable toggle normallybiased toward folded position for operation of the switching mechanism to. circuitopening position, said toggle having a rule-joint for extension of the toggle from folded to rigid position forleffecting operation of the switching mechanismto circuit-closing position, means including a linkage operable by and with the toggle for flexing the rule-joint as the switching mechanism attains circuit-closing position, and means for releasably holding the flexed toggle against folding actuation for sustaining the switching mechanism in circuit-closing position.

22. In apparatus of the class described, in combination, an electrical circuit including switching mechanism for opening and closing the circuit,

erating mechanism for theswitching mechanism including a foldable toggle normally biased toward folded position for operation of the switching. mechanism to circuit-opening position. said toggle having a rule-joint for extension of the toggle from folded to rigid position for eil'ecting operation of the switching mechanism to circuitolosing position, and means for actuating the toggle in rigid extended position for eil'ecting circuitclosing operation of the switching mechanism.

23. In apparatus of the class described, in combination, an electrical circuit including switching mechanism for opening and closing the circuit, operating mechanism for the switching mechanism including a ioldable toggle normally biased toward folded position for operation oi. the switching mechanism to circuit-opening position, said toggle having a rule-joint for extension of the toggle from folded to rigid position for effecting operation of the switching mechanism to circuitclosing position, and means electrically operable ior actuating the toggle in rigid extended position for eflecting circuit-closing operation of the switching mechanism.

24. In apparatus of the class described, in comation, an electrical circuit including switching mechanism for opening and closing the circuit, operating mechanism for the switching mechanism including a ioldable toggle normally biased toward folded position for operation of the switching mechanism to circuit-opening position, said toggle having a rule-joint for extension of the toggle from folded to rigid position for effecting operation of the switching mechanism to circuitciosing position, and means including a magnetcoil, an armature for the coil, and a link-connection between the armature and the toggle tor actuating the toggle in rigid extended position for effecting circuit-closing operation of the switch- 118 mechanism.

25. In apparatus of the class described, in combination, an electrical circuit including switching mechanism for opening and closing the circuit, dperatlng mechanism for the switching mechanism including a i'oldable toggle normally biased toward folded position for operation or the switching mechanism to circuit-opening position, said toggle having a rule-joint for extension of the toggle from iolded to rigid position for effecting operation of the switching mechanism to circuitclosing position, and means including an oscillatory lever having pivoted connection with an end of the toggle for actuating the toggle in rigid extended position for effecting circuit-closing operatio'n oi the switching mechanism.

26. In apparatus oi the class described, in combination. an electrical circuit including switching mechanism for opening and closing the circuit, operatingmechanism for the switching mechanism including a Ioldable toggle normally biased toward folded position for operation or the switching mechanism to circuit-opening position, said ,flpggle having a rule-joint for extension of the toggle from folded to rigid position for effecting operation of the switching mechanism to circuitclooinl position, and means including an oscillatory lever having pi oted connection with an end of the toggle, and an electro-responsive device co-operable with the pivoted connection oi! h the lever for actuating the toggle in rigid extended position for effecting circuit-closing operation of the switching mechanism.

27. In apparatus of the class described, in (70111-- bination, switching mechanism and operating means for the switching mechanism including a foldable toggle normally biased toward folded position for operation of the switching mechanism to circuit-opening position, said toggle having a rule-joint for extension from folded to rigid position for operation of the switching mechanism to circuit-closing position, means for actuating the toggle in rigid extended position for effecting circuit-closing operation of the switching mechanism, a linkage operable by and with the toggle for flexing the rule-joint as the mechanism attains circuit-closing position, and means for releasably holding the flexed toggle against folding actuation for sustaining the switching mechanism in circuit-closing position.

28. In an electric circuit interrupting apparatus, the combination with a circuit-breaker and its circuit, the circuit-breaker comprising co-operable contact-members swingably shiftable into and out of engagement for respectively closing and opening the circuit, of means including a first toggle actuable to extended position for shifting the contact-members into circuitclosing engagement, a spring biased on circuitclosing engagement of the contact-members for folding the toggle for shifting the contact-mcmbers to open the circuit, and electrically responsive second toggle-means included in the circuit for restraining the first toggle in circuit closing position during how of normal current in the circuit.

29. In an electric circuit interrupting apparatus, the combination with a circuit-breaker and its circuit, the circuit-breaker comprising co-operable contact-members swingably shittable into and out of engagement for respectively closing and opening the circuit, of means including a first toggle actuable to extended position for shifting the contact-members into circuitclosing engagement, a. spring biased on circuitclosing engagement of the contact-members for folding the toggle for shifting the contact-members to open the circuit, and second toggle-means magnetically associated with the circuit for restraining the first toggle in circuit-closing position during flow of normal current in the circuit.

30. In an electric circuit interrupting apparatus, in combination, a circuit breaker comprising co-operable contact-members swingably actuable into and out of engagement for respectively closing and opening the circuit, means including a toggle and a spring for biasing the toggle for swingably actuating the contact-members in circuit-opening direction, and electrically actuable means for actuating the toggle for closing the circuit at the contact-members.

31. In an electric circuit interrupting apparatus, in combination, a circuit-breaker comprising co-operable contact-members swingably actuable into and out of engagement for respectively closing and opening the circuit, means including a toggle and a spring for biasing the toggle for swingably actuating the contactmembers in circuit-opening direction, and electrically actuabie means for actuating the toggle for closing the circuit at the contact-members, said means including a magnet coil, an armature for the coil, and a link connection between the toggle and the armature.

LYMAN C. REED. 

